spbague



(No Model.) 2 sneets-sheet 1.

F. J. SPRAGUE.

BLEGTRO DYNAMIC MOTOR. No. 337,794. Patented Mar. 9, 1886` (No Model.) 2 Sheets- -Sheet 2. F. J. SPRAGUE.

ELEGTRO DYNAMIC MOTOR.

No. 337,794. Patented Mar. 9, 1886.

v series of short blocks.

UNITED STATES PATENT OFFICE.

FRANK J. SPRAGUE, OF NEV YORK, N. Y.

ELECTRO-DYNAMIC MOTOR.

PECIFIC'ATION forming part of Letters Patent No. 337,794, datecl March 9, 1886.,

(No model.)

iNew York, in the county and State of New York, have invented a certain new and useful lmprovement in Electro-Dynamic Motors, of which the following is a specification.

The object of this invention is to provide a simple switch, by means of which all the different Operations requisite in the regulation of electro-dynamic motors upon constant potential circuits may be readily performed that is, the motor maybe placed in circuit with low potential at the annature-terminals and strong field-magnet. The potential at the armature-terminals may then be gradually raised, and the field-maguet strength may then be weakened to increase the speed of the inotor, or the field Varied in one way or the other to properly regulate the speed, all these operations being performed without the use of any external resistance, but simply by changing the connections of the armaturc and fieldmagnet terminals.

My invention is illustrated in the accompanying drawings, in which Figure 1 is a view of the motor in elevation, with a plan View of the switch and diagram of the connections; Fig. 2, a section of the switch; and Figs. 8, 4, 5, 6, and 7 are diagrams illustrating the operations eifected by the movement of the switch.

A is the field-magnet, and B the armature, of a shunt-wound clectro-dynamic motor.

The regulating-switch consists of a base, C. of insulating material, on which are mounted a number of short contact-blocks, a a' &c., and three longer blocks, b, b', and b, situated one at each end and one in the middle of the Contact b' has an extension or shoulder, b. The moving portion of the switch is a two-part metal disk, D D', the two parts being' joined together mechanically, but divided electrically by a knob or block, E, of suitable insulating` material carried on a spin dle, F. This knob or block preferably has a metal cap, G, and it forms a handle for turning the disk. Part D of the disk has a projecting finger, c, of such1 length as to engage with the short contacts a. a', 8:0. The long contacts b, 2),, and b'l engage with the body of the disk. 1 2 are the main conductors of the constant potential circuit. Vire 3 leads to a biudingpost, d, of the switch, which is one terminal of the motor, being connected by a wire, 5, passing` underneath base C,with long contact b', which rests on the movable disk, and wire 4 from conductor 2 is connected with short contact a, from which wire 6 goes to binding-post d', which is connected by Wire 7 with commutator-brush f, and from contact a also a wire, 8, extends to the beginning ot' the main field-coils H. Contact a thus forms a terminal of the armature and main tield-shunts. The other armature-terminal is contact ai, to which wire 9 extends fi om commulator-brush f', and the other terminal of field-coils H is long` contact 1/1, the connection being by Wire 10. There is also a series of field-coils, H', the connection of one of whose terminals is changed to regulate the field. This terminal is block l connected through wire 10, which extends from point where the two field-coil sets are joined. The other terminal of coils H' is block aT through wire ll. Each sct ot' field-coils is connected at intervals with the intermediate short contact-blocks by wires 12 to 17, as will be explained. Blocks b and (L7 are connected together by wire 18.

In the position of the switch shown iu Fig. 1 the interval circuits of the motor are as follows: from binding-post (Z by wire 5 to long contact b', part D' of the disl ,'contact D2, wire 10 to g, where the current divides, part passing through all the coils H, and by wire Sto block a, and thence to conduetor 2, while the other part passes from g through all the coils H', and by wire 11 to block al, wire 1.8 to block Z), to D, by finger c to block a, and to conductor 2. There is also a connection between bl ocks al and a through the armature by means of wires 9, 7, and 6; but practically no current passes here, the armature being short-circuited by the direct connection across the regulatingswitch. This is the condition proper when the motor is started, there being low differ ence ofpotential at the armature'terminals and a strong field, as all the'field-coils are arranged to act together when their terminals are in this position. Turning the disk D D' in the direction shown by the arrow h (all the other arrows indicate direetion of current) first brings the finger c' into contact with block a. The Circuit is then as follows: from (Z via IOO b' D' b2 to g, where it divides, part going 'via all of H' to 11a7 9, the armature B 7 d' 6 as in Fig. 4, the difference of potential at the armature-cireuit terminals being raised by shunting it upon a portion of field-coils H, WhileV the strength of the field-magnet remains nearly the same. By moving the finger c along the successive contact-blocks the armature is progressively shunted upon all the coils H, While the conneotions of the field-coils remain unchanged, and thus the difference of potential at the armature-terminals is increased to the desired point. When the finger c reaches long block b', the circuits are as seen in Fig. 5, the coils H' being short-circuited. It is not thought necessary toparticularly describe the circuits in all the different positions of the contact-finger. The cutting` out of coils H' weakeus the field-after full potential is attained at the armature-cireuit terminals-so as to increase the speed of the motor. The extension ba permits contact a* to be made before contact b' D' is broken. VVhen c reaches at, it will be seen that the first connection is by Wire 15, which extends to a point between vcertain sections of H'. The current thus has two paths in opposite directions in H', and therefore the magnetizing effect of certain of' said coils is reversed, as seen in-Fig. 6, and thereby the field is additionally Weakened. The further movement of the disk reverses the current in additionalcoils H' until long block b is reached by finger c, When all the coils H' are reversed and the field is a't its weakest point. While the motor is running, the regulation is 'accomplished by moving finger c along blocks b' to 62, and thereby increasing 01' decreasing the magnetizing effect of coils H',

What I claim is- 1. The combination, 'with an electro dynamic motor, of a regulating-switch having contacts forshort-oircuitingthearmature,contacts for 'shunting the armature upon more or less of the field-coils, and contacts for reversing the current in more or less of the field-coils, substantially as set forth.

2. The combination, in an electro-dynamic motor, of field-coils in shuntrelation to the armature, field-coils in series with the armature, and means for reversing the current in more or less of said series coils, substantially as set forth.

3. In an electro-dynamic motor, the combination of main field-coils, the'armature shunted upon a variable number of said main fieldcoils, other field-coils in series with the armaature, and means for reversing the current in more or less of said series coils, substantially as set forth. i

4. In an electrodynamic motor, the combination of the armature, main field-coils, other field-coils in series with the armature, and a conductor extending from between the armature and the series field-coils, and having a movable terminal, whereby said conductor may be made to short-cireuit the armature or to 'shunt the armature upon more or less of the main field-coils, substantially as set forth.

5. In an electro-dynamic motor, the combi- ,nation of the armature, main field-coils, other field-coils in series With the armature, and a movable terminal of said series coils adapted to short-cireuit them orto reverse the current in more or less of them, substantially as set forth.

6. In an electro-dynamic motor, the combination of the armature, main field-coils, other field-coils in series With the armature, a conductor extending from between the armature and the series field-coils, and having a movable'terminal', whereby saidconductor may be made to shortcireuit the armature or to shunt the armaturev upon more or less of the main field-coils, and a movable terminal'of said series coils adapted to short-cireuit them or to reverse the current in more or less of them, substantially as set forth.

7. The combination, with an electro-dynamic motor having two sets of field-coils, of means for changing one set from shunt to series relation with the other, substantially as set forth.v

`8. The combination, with an electro -dynamic motor having` two sets of field-coils, of means for changing one set from shunt to series relation with the other, and for reversing the current in the 'set so changed, substantially as set forth.

9. In a regulating-switch, the combination, with the long and short contacts, of the rex'olving two-part disk, one part having a vcontact-finger adapted to engage with said short contacts, substantially as set forth.

This speeification signed and witnessed this 2d day of May, 1885.

FRANKv J. sPRAGUE.

Vitnesses:

A. W. KIDDLE, E. C. RowLAND. 

